A motor vehicle generally utilizes a propshaft to connect a transmission or power takeoff unit to a driving axle. Sometimes during operation of the motor vehicle undesired or objectionable noises are generated by high-speed rotation of the propshaft. One particularly troublesome source of propshaft noise is caused by breathing mode vibrations that can be perceived by the human ear as a ringing or a clunking type of noise. Breathing mode vibrations are typically defined as the radial expansion or contraction of an outer surface of the propshaft during operation.
One known solution to reduce noise created by the breathing mode vibrations is to place sound absorbing materials, such as cardboard or foam fillers, within the propshaft. However, using sound absorbing materials within a propshaft may have several disadvantages. For example, the sound absorbing materials can only be placed within the propshaft prior to propshaft being assembled in a vehicle. Some types of sound absorbing materials may affect the balance of the propshaft. Also, at least some sound absorbing materials may not be able to withstand the elevated temperatures created by an exhaust system during vehicle operation. Finally, sound absorbing materials only mask and do not directly alleviate the underlying cause of the propshaft noise.
Thus, there exists a need for a component that reduces the breathing mode vibrations of a propshaft to eliminate the noises head by a vehicle operation.